#!/bin/sh

# run from directory where this script is
cd `dirname $0`
EXAMPLE_DIR=`pwd`

# check whether echo has the -e option
if test "`echo -e`" = "-e" ; then ECHO=echo ; else ECHO="echo -e" ; fi

$ECHO
$ECHO "$EXAMPLE_DIR : starting"
$ECHO
$ECHO "This example shows how to calculate Fermi surfaces colored with the Fermi velocity and projections."

# set the needed environment variables
. ../../../environment_variables

# required executables and pseudopotentials
BIN_LIST="pw.x fermi_velocity.x projwfc.x fermi_proj.x"
PSEUDO_LIST="Mg.pbe-n-kjpaw_psl.0.3.0.upf B.pbe-n-kjpaw_psl.0.1.upf"

$ECHO
$ECHO "  executables directory: $BIN_DIR"
$ECHO "  pseudo directory:      $PSEUDO_DIR"
$ECHO "  temporary directory:   $TMP_DIR"
$ECHO "  checking that needed directories and files exist...\c"

# check for directories
for DIR in "$BIN_DIR" "$PSEUDO_DIR" ; do
    if test ! -d $DIR ; then
        $ECHO
        $ECHO "ERROR: $DIR not existent or not a directory"
        $ECHO "Aborting"
        exit 1
    fi
done
for DIR in "$TMP_DIR" "$EXAMPLE_DIR/results" ; do
    if test ! -d $DIR ; then
        mkdir $DIR
    fi
done
cd $EXAMPLE_DIR/results

# check for executables
for FILE in $BIN_LIST ; do
    if test ! -x $BIN_DIR/$FILE ; then
        $ECHO
        $ECHO "ERROR: $BIN_DIR/$FILE not existent or not executable"
        $ECHO "Aborting"
        exit 1
    fi
done

# check for pseudopotentials
for FILE in $PSEUDO_LIST ; do
    if test ! -r $PSEUDO_DIR/$FILE ; then
       $ECHO
       $ECHO "Downloading $FILE to $PSEUDO_DIR...\c"
            $WGET $PSEUDO_DIR/$FILE $NETWORK_PSEUDO/$FILE 2> /dev/null
    fi
    if test $? != 0; then
        $ECHO
        $ECHO "ERROR: $PSEUDO_DIR/$FILE not existent or not readable"
        $ECHO "Aborting"
        exit 1
    fi
done
$ECHO " done"

# how to run executables
PW_COMMAND="$PARA_PREFIX $BIN_DIR/pw.x $PARA_POSTFIX"
PROJWFC_COMMAND="$PARA_PREFIX $BIN_DIR/projwfc.x $PARA_POSTFIX"
FERMI_PROJ_COMMAND="$BIN_DIR/fermi_proj.x "
FERMI_VELOCITY_COMMAND="$BIN_DIR/fermi_velocity.x "
$ECHO
$ECHO "  running pw.x as:             $PW_COMMAND"
$ECHO "  running projwfc.x as:        $PROJWFC_COMMAND"
$ECHO "  running fermi_velocity.x as: $FERMI_VELOCITY_COMMAND"
$ECHO "  running fermi_proj.x as:     $FERMI_PROJ_COMMAND"
$ECHO

# self-consistent calculation
cat > mgb2.scf.in << EOF
&CONTROL
 calculation = 'scf',
  pseudo_dir = '$PSEUDO_DIR/',
      prefix = 'mgb2' ,
      outdir = '$TMP_DIR/'
/
&SYSTEM
       ibrav = 4,
   celldm(1) = 5.808563789,
   celldm(3) = 1.145173082,
         nat = 3,
        ntyp = 2,
     ecutwfc = 50.0 ,
     ecutrho = 500.0 ,
 occupations = 'tetrahedra_opt',
/
&ELECTRONS
/
ATOMIC_SPECIES
 Mg    24.3050   Mg.pbe-n-kjpaw_psl.0.3.0.upf
  B    10.811    B.pbe-n-kjpaw_psl.0.1.upf
ATOMIC_POSITIONS crystal
 Mg    0.000000000    0.000000000    0.000000000
  B    0.333333333    0.666666667    0.500000000
  B    0.666666667    0.333333333    0.500000000
K_POINTS automatic
 16 16 12 0 0 0
EOF
$ECHO "  running the scf calculation for MgB2...\c"
$PW_COMMAND -in mgb2.scf.in > mgb2.scf.out
check_failure $?
$ECHO " done"

$ECHO
$ECHO "  Fermi velocity at the Fermi surface ..."

$FERMI_VELOCITY_COMMAND -in mgb2.scf.in > FS_vf.out
check_failure $?

$ECHO
$ECHO "  Calcuration of projections of atomic orbitals ..."

cat > mgb2.proj.in << EOF
&projwfc
   outdir = '$TMP_DIR/'
    prefix='mgb2'
    Emin=-0.3422,
    Emax=10.0578,
    DeltaE=0.1
/
2
6 10
EOF
$ECHO "  running projection calculation for MgB2...\c"
$PROJWFC_COMMAND -in mgb2.proj.in > mgb2.proj.out
check_failure $?
$ECHO " done"

$ECHO
$ECHO "  Orbital projections at the Fermi Surface..."

#
# Step 2b-2. Run proj_fermi.x
#
$ECHO ""
$ECHO "grep state mgb2.proj.out"
$ECHO ""
grep state mgb2.proj.out
#
$ECHO ""
$ECHO " Compute B2pz-projected (Wfc6+Wfc10) fermi surfaces."
$ECHO ""
$FERMI_PROJ_COMMAND -in mgb2.proj.in > FS_b2pz.out
check_failure $?
$ECHO "mv proj.frmsf b2pz.frmsf"
mv proj.frmsf b2pz.frmsf

$ECHO
$ECHO "  Use 'fermisurfer results/b2pz.frmsf' to plot the Fermi Surface"

$ECHO "  cleaning $TMP_DIR...\c"
rm -rf $TMP_DIR/mgb2.*
$ECHO " done"

$ECHO
$ECHO "$EXAMPLE_DIR: done"
